Head traverse mechanism for radial drills



P 1942- w. e. HOELSCHER 2,295,516

HEAD TRAVERSE MECHANISM FOR RADIAL DRILLS Filed Augf21, 1939 3Sheets-Sheet l BY v I W "Mumm l 1942- w. G. HOELSCHER 2,295,516

HEAD TRAVERSE MECHANISM FOR RADIAL DRILLS Filed A 21, 1959 sSheets-Sheet 2 v H INVENTOR. WM/Ja WMTToRNEya,

I lllmumn "mum umummm Sept. 8, 1942. w. G. HOELSCHER I HEAD TRAVERSEMECHANISM FOR RADIAL DRILLS Filed Aug. 21, 1939 3 Sheets-Sheet 3INVENTQR. $4464 ATTORNEYS.

Patented Sept. 8, 1942 HEAD TRAVERSE MECHANISM FOR RADIAL DRILL WilliamG. Hoelscher, Cincinnati, Ohio, assignor to The American Tool WorksCompany, Cincinnati, Ohio, a corporation of Ohio ApplicationAugust 21,1939, Serial No. 291,110

6 Claims. (CI. 77-21) This invention relates to machine tools and isparticularly directed to an improved mechanism for traversing the headof a radial drill along the rail and to means for controlling theoperation of the mechanism. More particularly, the invention isconcerned with the mechanism for traversing the head either by power orby hand.

Primarily, it has been the object of the present inventor to provide anapparatus for driving the rack engaging gear either by means of powerderived from the main drive shaft or by means of a hand wheel, whereinthe hand power means is disconnected when the power driven means isconnected. More particularly as to this, it has been the object toprovide means whereby the mechanism, when the head is at rest, i coupledto the hand wheel and is therefore in position for immediate handactuation without actuation of the control lever.

It has been the still furth r object of the present inventor to provideimproved reversing means and coupling means for the power drivenapparatus. Additionally, a single lever is provided at the front of thehead for moving the control from normal balanced neutral hand feedposition to either right or left hand drive and at the same timecoupling the power mechanism to the rack gear in either of the reversepositions of drive. When released the lever returns or permits thereturn of the coupling means to normal position for hand actuation.

Other objects relate to the specific construction of the control whereinvery little force is required to couple and uncouple the powerconnection; wherein release of the control lever permits it to return tobalanced neutral position automatically; wherein a novel interlockarrangement is effective for establishing positively the positions ofthe lever; wherein the coupling of power is brought about through springmeans and wherein the actuation of the reversing clutch is effectedthrough an improved screw and nut combination rendering the actuationmore easily performed and more easily spring returned to neutral. Thegeneral arrangement of parts is extremely compact in the base of thehead.

Other objects and certain advantages will be more fully apparent from a,description of the drawings in which:

Figure l is a front view of a radial drill incorporating the presentimprovements.

Figure 2 is a sectional view taken on line 22, Figure 1, illustratingimproved mechanism more in detail.

Figure 3 is a fragmentary rear View of the drill partly in section,illustrating the transmission of the power from the motor to the headtraversing mechanism.

Figure 4 is a sectional view taken on line 44,

Figure 2, showing the means for coupling either the hand or the powerfeed to the rack engaging gear.

Figure 5 is a sectional view taken on line 5-5, Figure 2, furtherdetailing the driving and coupling means assembled on the rack engaginggear shaft.

Figure 6 is a sectional view taken on line 6B, Figure 4, furtherillustrating the coupling means of Figure 4.

Figure '7, is a sectional view taken on line l!, Figure 6, detailing theinterlock means for establishing the alternate coupling positions.

Figure 8 is a sectional view taken on line 8-8 of Figure 2, showing themeans for balancing the lever at neutral.

Referring to the drawings, particularly Figures 1 and 3, the base of theradial drill is indicated at H), the stump at II, and the column at I 2.The column I2 is rotatable on the stump, and the arm [3 is verticallyadjustable on the column by means of the screw M. The arm carries thedrill head l5 and includes ways I6, along which the head is traversed. Amotor l1, mounted on the end of the arm adjacent to the column drives ashaft l8, which, through meshing gears l9 and 20, drives the shaft 2|,journaled in the arm and extending along the back thereof.

The shaft 2| traverses the head I5 and is splined and carries a gear 22thereon within the head. This gear drives a gear 23 carrying a gear 24in mesh with a gear 25 which in turn carries the bevel gear 26 meshingwith the bevel gear 21 appearing in Figure 2.

The bevel gear 2! is fixed to and drives a vertical shaft 28. This shaftis journaled in ball bearings 29 fixed in a bearing bracket 30 carriedin a horizontal wall of the head. A bevel gear 3| fixed to the lower endof the shaft 28 meshes with spaced bevel gears 3233 loosely journaled onball bearings on the shaft 34. The shaft 34 is journaled in the rearwall of the head and in spaced lugs 35-36 within the head.

These bevel pinions are cylindrical andare internally supported in eachinstance on a double ball bearin 31. A sleeve 38 is keyed to the shaft.A set of clutch Plates 39 is provided for each reversing gear betweenthis sleeve and the gears. A coil spring 49 is provided for each set ofclutch plates. These springs are ancing means at the controllever 4-5 atthefront of the head when the lever is released.

This yoke 4| is slid along the sleeve by means of a nut 42 traversed bya screwelement 43. The screw element 43 is pinned to acontrol rod 44rotatably journaled in bearings in the front and back walls of the head.This rod extends through the front of the head and carries the controlhandle 45. The nut is fixed to a guide rod 46 extended through the nutbelow the screw element and slidably mounted in the lug 35 and the backwall of the head. Rotation of the control rod by means of the handle 45traverses the nut in one or the other direction and. couples thecorresponding reversing gear. The threads of the screw element have an.extremely coarse lead so as to move the clutching means sufiicientlywith very little movement of the lever. It is believed unnecessary todiscuss the exact details of the clutches since the specific structureof the clutches does not form a part of this invention.

The control rod is sectional. The sections are joined through a sleevejoint or tongue and groove connection within a support bushing 41 in thelug 35. The extreme forward end of the rod beyond thefront wallof thehead is journaled in a bushing 48 carried by the front cover 49 of thehead. The balancing device for returning the rodto neutral, is mountedbetween the cover and the front wheel of the head.

This device (Figure 8) consists of a supporting element 50 fixed to thewall of the head by means of screws This element provides spaced bosses52 traversed by a rod 53. An arm 54 is pinned to the control rod andcarries a pin 55 in its lower end extended into a notch 56 in the rod 53whereby swinging of the arm slides the rod in the lugs 52-52. The rod ismade up of sections to provide a reduced diameter portion exactly equalin length to the distance between the lugs. Washers 5'! are engagedagainst the respective shoulders thus formed, and against the lugs.Acoil-spring 58 is disposed under compression about the reduced diameterportion of the rod and between. the washers.

The sliding movement of the rod in either direction will causecompression. of the spring between the washers and the spring willreturn the washer, which has been moved, to its normal position as soonas the lever is released. Thus the lever will always return to thecentral position shown in Figure 8 when it is released, and will returnthe clutching mechanism toneutral.

The driving assembly for the rack gear 60 is shown in Figure 5. Thisrack gear meshes in the conventional manner with the rack 6| (Figure 2).The shaft 62 which carries the gear 60 is journaled in ball bearings inthe upper and lower walls of the head. A driving sleeve 63 is keyed tothe shaft 52. A shiftable coupling element 64 is in splined connectionwith the sleeve. This coupling element 64 includes teeth 65' on itsupper end, and teeth 66 on its lower end. The upper teeth mesh with theteeth 61 of a loosely rotatably mounted worm wheel 68, which wheel isconnected with the power means. The lower teeth mesh with the teeth 69of a bevel gear 10 loosely rotatably mounted on the shaft and rotated bymeans of the hand Wheel 1| through a pinion 12.

A nut 13 screwed on the shaft holds the driving sleeve 63 againstawasher 14 engaged against a sleeve 15 against the bearing assembly. Thegear 68 is supported between the bearing assembly and the washer 14 uponthe sleeve 15. The shaft 62 is loosely piloted within a lower sleeve I6having a headed upper end and drawn down against the top of the gear 10by means of a nut 11- screwed on the lower end against the inner-race ofthe lower bearing.

The teeth of the gear I0 are on a depressible element 18 of the gearwhich takes up the shock of coupling and permits yielding when the teethmeet end to end. The element 18 is splined within the bore of the gearand is engaged upon coil springs 19.

The drive shaft 34 carries a worm. 80. in mesh withthe worm wheel 68.and thus driving rotation is imparted to the gear 68 in one or the otherdirection. depending on clutch operation. The coupling element 64 isshifted by means of a yoke 82 (Figures 4 and 6) having the usual pin andgroove connection to the coupling element. This yoke-is. loosely mountedon the shift rod 44 and is spring urged toward power coupling or upperposition by means of a coil spring 83 disposed under tension between an.arm 84 of the yoke and a. pin85 on the head.

Unless otherwise restrained, the yoke would thereby couple the power.However, it is held downwardly in hand drive coupling position by awedge or interlock element 88 bolted to the underside of the rod 89.This rod is shifted by means of a lever 90 pinned to the shifter rod andhaving its swinging end disposed in a slot in the lever. With. the shiftrod. in neutral position the Wedge element or cam 88 is in engagementwith a-. pin 9-! extending. from the shifter arm of the yoke 82. Whenthe shifter rod is moved to one side or the other the cam is moved outof connection with the pin and the spring 83. is effective for engagingthe coupling means with the power driven gear 68. Thus twoacts occurwhen the hand traverse lever is moved either to the right or the left.First the power is coupled to one or the other of the reversing gears.Second, the power is coupled to the rack driving gear. shaft through thecoupling means 64. The hand wheel, accordingly, is stationary While thehead is being power traversed. The coupling movements are thusinterlocked. The power coupling takes place under the action of thespring. 83 when released by displacement of the cam or wedge 88 from thepin 9|.

Having described my invention I claim:

1. Mechanism for traversing the head of a radial drill along the arm.thereof, including the rack on the armandthe gear on the head mesh ingtherewith, comprising; a shaft for said gear, a power driven gearloosely rotatably mounted on the shaft, a. hand driven gear looselyrotatably mounted on the shaft, a coupling element in splined drivingconnection with the shaft, means for shifting said coupling element fromcoupling engagement with said power driven gear to cou pling engagementwith said hand driven gear or vice versa, said coupling element normallyheld in coupling engagement with the hand operated gear, power mechanismincluding reversing clutches for driving said power driven gear and, acontrol lever operatively connected with the clutches and with the meansfor shifting the coupling element whereby the coupling element isconnected to the power driven gear when either of the clutches isengaged.

2. An apparatus for traversing the head of a radial drill along the armthereof, including the rack on the arm and the gear on the head meshingtherewith, comprising; a shaft for said gear, a power driven gearloosely rotatably mounted on the shaft, a hand driven gear looselyrotatably mounted on the shaft, a hand wheel constantly in mesh withsaid hand driven gear, a coupling element in splined driving connectionwith the shaft, means for shifting said coupling element into engagementwith and between said hand driven gear and power driven gearrespectively, said coupling element normally held in coupling engagementwith the hand operated gear, power mechanism including clutching meansfor driving said power driven gear and, a control lever operativelyconnected with clutching means and with the means for shifting thecoupling element whereby the coupling element is connected to the powerdriven gear when the clutching means is engaged.

3. Apparatus for traversing the head of a radial drill along the armthereof, including the rack on the arm and the gear on the head meshingtherewith, comprising; a power driven gear, a hand driven gear, acoupling element for connecting either of said driven gears to the rackgear, power mechanism including reversing clutches for driving saidpower driven gear, a control lever operatively connected with theclutches and with the coupling element whereby the coupling elementconnects the power driven gear to the rack gear when either of theclutches is engaged and spring means for moving the coupling element topower coupling position.

4. In a traversing mechanism for the head of a radial drill includingthe head mounted on the arm and a gear on the head engaging a rack onthe arm; a power transmission for driving said gear including reversingclutches, said transmission located entirely at the rear of the head, acontrol rod extending across the base of the head from the front to theback, a lever for rotating the rod, a connection for the rod to theclutches, and means for balancing the lever at neutral.

5. A head traversing mechanism comprising a power shaft, reversingclutches on the power shaft, said clutches including in each instanceclutch plates and springs for coupling the plates, a shifter collardisposed between the springs, lever means for shifting the collar in oneor the other directions, and means for balancing the shifting means atneutral, said means incorporated in the shifting means, said clutchsprings normally completely released when the shifting means is atneutral.

6. A head traversing mechanism comprising, a power shaft, reversingclutches on the power shaft, said clutches including in each instanceclutch plates and springs for engaging the plates, shifting means forengaging one or the other of the springs, and means for balancing saidshifting means at neutral said clutch springs normally completelyreleased when the shifting means is at neutral.

WILLIAM G. HOE-LSCHER,

